one coin is seven more than twice as old as another. Represent the ages of the coins using a single variable.

x = age of coin 1

7 + 2*x = age of coin 2.

Step-by-step explanation:

We have two coins, let's denote the ages as:

x = age of coin 1

y = age of coin 2.

Then, the statement is:

"one coin is seven more than twice as old as another."

let's suppose that this refers to y, then:

y = 7 + 2*x

So now we can represent the ages of both coins with only one variable, x.

x = age of coin 1

7 + 2*x = age of coin 2.

5

step-by-step explanation:

or

step-by-step explanation:

we need to solve for 'x' the following equation:  

we have that:

⇒

⇒ ⇒

factorizing, we get that:

  ⇒

then, the solutions are: or

nothing extraneous has been found!